When good news goes bad: Antibiotics for low back pain

A few months back, I had a call from my parents-in-law.  Over breakfast that morning they had read an article in our local newspaper, The Press, about how antibiotics might be the cure for low back pain, and they wondered if I had seen it.

At that stage I hadn’t but since then I’ve been watching the story with interest – and as it turns out there has been a bit of a hoo-ha over it¹…

The Good

In April this year, a group of researchers from Denmark published the results of a rather interesting study in the European Spine Journal ². Here’s the essentials of the research:

• Double blinded RCT
• 162 subjects with Chronic Low Back Pain and “Type1 Modic changes” on MRI
• Treated with either 100 days of antibiotics (amoxicillin clavulanate) or 100 days of placebo.

(If you are interested in the nuts and bolts of the study - you can get that here) The results were, well… pretty impressive. The antibiotic group improved on all of the outcome measures used, and enjoyed a statistically and clinically significant reduction in both pain and disability compared with the placebo group.   Some of the lucky souls who got the antibiotics were still improving at one-year follow up.  As I said, pretty impressive stuff. The treatment - Modic Antibiotic Spinal Therapy ( MAST) -  is based on the observation  that Type 1 Modic changes show up on MRI in about 6% of the general population but in 35-40% of people with chronic low back pain.  The theoretic basis behind the antibiotic treatment is that modic changes  are result of inflammation caused by low virulence anaerobic organisms infecting the discs. Treat the infection – and viola! See ya later chronic low back pain… Now, the trial itself seems to have been relatively well conducted.  As with any trial, a few criticisms of the methodology have been raised, but overall the research results seem pretty robust. What has created the hoo-ha is the way those results have been reported.  

The Bad

At the time the study was published – well… nothing much happened. Fearing that their results might go unnoticed and eager to avoid a repeat of the Helicobacter Pylori / Stomach Ulcer story, the researchers organised a press conference in May to try to create some media interest in their results. Well – the ploy worked.  The media got interested and the story was picked up by mainstream media, across the globe. The quality of the reporting varied from down and out sensationalism to more balanced, responsible journalism.  Sadly though, the vast majority seemed to subscribe to the  “why ruin a good story with the details” school of reporting- calling for Nobel prizes and promising  a cure for ½ million kiwis with back pain. The problem is, that while the results of the trial were promising, they weren’t that good.

• Patients with Type 1 Modic Changes is likely to represent only a small, subgroup of the chronic low back pain population
• The improvement in pain among the Antibiotic group was significant, but it was only in the magnitude of 3 points on a Visual Analogue Scale (from 6.7/10 to 3.7/10) - while this might be "significant" it hardly represents a "cure"

Balancing these points with the downsides that widespread long term, antibiotic prescription might pose, there’s not quite as much to get excited about as the newspaper would have you believe. While antibiotics might work for a very specific type of patient in very specific circumstances, it’s really still too early to tell and the results should be taken with a grain of salt until the study can be replicated. The authors themselves close their report by saying "we rely on our fellow colleagues to use clear evidence-based criteria and to avoid excessive antibiotic use" and "more confirmatory work in other populations and studies on improved protocols as well as the background science should be encouraged".  

The Ugly

As a result of the way the story was run by the media, the authors of the paper have received a fair amount of flak from the scientific community, including scrutiny about a possible conflict of interest.  It looks like they must have spent the last few months answering hate mail if this months ESJ contents page is anything to go by. At the end of the day I for one feel a bit sorry for them.  To borrow a quote from Harriet Hall “This was a well-designed study, carefully carried out, with a credible rationale, impressive results, and a cautious interpretation. This is how science should be done” It’s the media who should be in the naughty corner.  

The Question

Reports of patients asking about MAST as a result of the media coverage are starting to be reported in the blogging world. I’m interested if this has reached our part of the woods yet? Let us know:

• Did you see the story published in mainstream media, and if so, where?
• Has anyone seen a patient asking for MAST as a result of reading the media coverage of the study?
• Are there other examples from the past, of media reports of a scientific study changing patient behaviour?

  ¹ hoo-ha or hoo-hah  n. Slang  1. A fuss; a disturbance: "the subject of this last hoo-hah" (William Safire).  2. A chortle or laugh: got a good hoo-ha out of that story ² Albert HB, Sorensen JS, Christensen BS, Manniche C. Antibiotic treatment in patients with chronic low back pain and vertebral bone edema (Modic type 1 changes): a double-blind randomized clinical controlled trial of efficacy. European Spine Journal. 22(4):697-707